Conveying mechanism in a folding machine for folded blanks



Jam 30, 1968 R. PRElSlG- 3,366,221

CONVEYING MECHANISM IN A FOLDING MACHINE FOR FOLDED BLANKS Filed Aug.25, 1966 2 Sheets-Sheet 1 F IG 3 /0 7,

2 ll l 8 Jam. 30, 1968 R. PREISIG CONVEYING MECHANISM IN A FOLDINGMACHINE FOR FOLDED BLANKS 2 sheets -sheet 2 Filed Aug. 25, 1966 UnitedStates Patent Office 3,366,221 CONVEYING MECHANISM IN A FOLDING MACHINEFOR FOLDED BLANKS Roland Preisig, Lausanne, Switzerland, assignor to J.Bobst and Son S.A., Prilly pres Lausanne, Switzerland Filed Aug. 25,1966, Ser. No. 574,996 Claims priority, application Switzerland, Aug.31, 1965, 12,216/65 11 Claims. (Cl. 198-33) ABSTRACT OF THE DISCLOSURE Aconveying mechanism in which a folded blank is placed on a flat outersurface of a conveying member which undergoes translational androtational movement while supporting the folded blank, the conveyingmember having a suction passage in communication with the openings inthe outer surface which is subjected to a vacuum during selectedportions of the path of travel of the conveying member to maintain thefolded blank against the outer surface of the conveying member, aguiding member being located adjacent the conveying member and extendingparallel to and adjacent the outer surface of the conveying member forengaging the folded blank and maintaining the folded condition thereofwhile the blank undergoes movement with the conveying member.

This invention relates to a conveying mechanism and more particularly toa conveying mechanism for folded blanks such as paper or cardboard.

In forming cardboard boxes or the like, blanks are cut to apredetermined profile, after which they are folded in a folding machinealong preivously upset lines.

Folding takes place in the course of the passage of the blanks throughthe machine.

Such folding, however, cannot always be effected without difiicultywhile maintaining a rectilinear conveying direction. Sometimes it isnecessary to turn the blanks crosswise during the course of folding.

As a result there are known so-called two coordinate folding machines,the frame of which has the shape of a square, making it particularlycumbersome.

To remedy this drawback, it has already been proposed, in a rectilinearmachine, to turn the blanks in their plane at a given moment duringtranslation, so as to avoid a temporary standstill which would interferewith continuous production.

The known conveying mechanisms employ a pair of coaxial rotary membersdisposed one above the other for gripping a blank between them andturning the blank in its plane while undergoing common translatorymotion.

However, the transported blanks generally are already partially folded,and these folds tend to open due to the elasticity of the cardboard orpaper, unless the folded condition of the blanks is maintained duringtheir transport.

The known mechanisms fail to achieve the above, since a continuousguiding surface for maintaining the folded condition of the blankscannot be provided either above or beneath the blank due to the requiredspace for the passing of the rotary members.

An object of the invention is to provide a conveying mechanism whichavoids the above deficiency.

A further object of the invention is to provide a conveying mechanism ina folding machine in which the folded condition of the transportedblanks is preserved during their transport.

In accordance with one embodiment of the invention, the conveying devicecomprises a conveying member adapted for receiving a folded blank andfor undergoing translational and rotational movement, said conveying3,3662% Patented Jan. 39, 1968 member having an outer surface forsupporting the blank in which surface are formed openings, means forestablishing suction in said openings to maintain the blank against theouter surface of the conveying member, and a guiding member locatedadjacent the conveying member and having a surface extending parallel toand adjacent the outer surface of the conveying member for engaging theblank and maintaining the folded condition thereof while the blankundergoes movement with the conveying member.

The invention will next be described in greater detail with reference toan embodiment thereof illustrated in the attached drawing, wherein:

FIG. 1 is a diagrammatical illustration in plan view of a foldingmachine;

FIG. 2 shows a device according to the prior art for conveying a blankin the machine of FIG. 1;

FIG. 3 is a schematic side view of the portion of the machinecorresponding to FIG. 2 in accordance with the invention.

FIG. 4 shows the conveying mechanism according to the invention insimplified fashion in perspective;

FIG. 5 is a transverse sectional view through the conveying mechanism;

FIG. 6 is a longitudinal sectional view through the conveying mechanismas taken along lines VIVI in FIG. 5;

FIG. 7 is a schematic elevation view of the overall conveying mechanism;and

FIG. 8 is a diagrammatic illustration of the conveying mechanism of FIG.7 with supply and removal means.

In FIG. 1 of the drawing there is shown a rectangular frame 1 of afolding machine for the folding of blanks. The blanks 2 are supplied tothe frame 1 at one end thereof and discharged therefrom at the otherend.

The machine is divided into two working zones A and B. In zone A theblanks are disposed transversely while being advanced through themachine, while in zone B they are disposed longitudinally while beingadvanced through the machine. Between zones A and B each blank isrotated a quarter of a turn in its plane from the position shown at 2 tothe position shown at 3'.

In the device according to the prior art, as shown in FIG. 2, the blank2 is gripped between two coaxial rotary members 4, 5 which undergoconcurrent rotation and translation in the direction of arrow 6.Generally, the blank has already undergone at least one foldingoperation and will present a folded flap 7 or the like. The flap 7 inthe arrangement of FIG. 2 is not maintained against the blank duringtransport thereof and due to the elasticity of the blank, the flap willtend to unfold as shown. In addition to the elasticity of the blank, thecentrifugal force developed by the rotation of the members 4, 5 and airresistance will also tend to unfold flap 7.

In FIG. 3 there is shown the arrangement according to the inventionwhereby the folded condition of the blank will be maintained during therotation and translation of the blank. More particularly, as shown inFIG. 3, a conveying member 8 supports the blank 2 and holds the samethereagainst by suction as a result of connection with a vacuum pump vialine 9. A plate 10 is disposed above the member 8 and engages the blankto maintain the flap 7 thereof in folded condition while the blankundergoes movement with the member 8. The plate 10 hasan absolutelysmooth lower surface enabling smooth sliding movement of the partlyfolded blank thereagainst. Preferably, the plate 10 will be transparentin order to enable the operator to visibly establish that the blanks areproperly being conveyed while their folded condition is maintained.

FIG. 4 shows in greater detail the arrangement of the mechanism of FIG.3.

In FIG. 4 there are seen a succession of conveying members 8 which passbetween two surfaces 11 and 12 located in a common plane. Each conveyingmember 8 comprises a rotatable member 14 centrally mounted in a supportmember or block 13. Each member 14 is provided with suction openings 14'for drawing thereagainst the blanks being transported on the surfaces 11and 12. The plate 10 extends above surfaces 11 and 12 and serves as aguiding member for the blanks to maintain the folded condition thereofwhile the blanks are transported.

Two successive blocks 13 are shown in FIG. 4 and these form a part of anendless chain of such blocks as will be described later.

Successive blocks 13 are connected by elastic bands 16 which completelyfill the spaces between surfaces 11, 12 and the successive blocks 13.

FIGS. and 6 show the construction of blocks 13 and how the rotatablemembers 14 are momentarily connected to a vacuum source duringtransport.

Each rotatable member 14 with its suction openings 14' is formed with afiat head portion, beneath which depends a partly hollow shaft 17 whichis rotatably mounted in the block 13. A nut 18 holds the member 14axially in the block 13.

The shaft 17 is hollow and is provided with lateral apertures 17' toprovide communication between the inside of the shaft and a lateralchamber 19 in the block 13. The block 13 passes, during transport, on arail member 20 which is provided with a vacuum chamber 21. The upperface of member 20 facing chamber 19 is formed with a series ofapertures. These apertures are normally closed by valve members in theform of balls 22 which are subjected to the action of springs 23. InFIG. 6, only one of these springs is shown.

A pump (not shown) creates a vacuum in the fixed lower chamber 21. Thepressure exerted by each spring 23 is sufiicient to overcome the suctionand normally maintains the valve member in closed position. A bar 24 issecured to each block 13 and passes on member 20 during the travel ofthe block.

During its passage on member 20, bar 24 contacts the balls 22 to pushthem into chamber 21 against the action of springs 23 and temporarilyestablish communication between the movable upper chamber 19 in theblock and the fixed lower chamber 21 in member 20.

In FIG. 6 is clearly shown how on its passage on the member 20 the block13 opens the valve members and thereby establishes suction in theopenings 14 in rotatable member 14. The bar 24 has a forwardlyprojecting portion with an upwardly slanting surface 24', allowing thebar to pass over the balls and lower them.

As seen in FIG. 5, the arrangement of the block 13 is for the most partsymmetrical, in the sense that the block 13 slides on a rail member 20similar with regard to member 20 and containing a vacuum chamber andball valves 22'. However, opposite the upper chamber 19 in the block 13,there is only a blind space or groove 19' and valve members 22' remainclosed. The significance of the latter will be shown later.

Laterally secured to the members 20 and 20' are fixed plates 26 whoseupper face serves as a support and a guide for chains 27 which connectsuccessive blocks.

This connection is shown diagrammatically in FIG. 7, wherein an endlesschain assembly of six blocks 13 is formed. The blocks 13 are connectedby the pairs of chains 27 which pass on chain wheels 28 and 29.

At the time of passage of the blocks 13 beneath the guiding member orplate 10, the blocks 13 slide on the rail member 20 as shown in FIG. 7in a simplified way. The blanks are fed between the blocks 13 and theplate in a manner to be described later. In the course of passage of theblocks 13 on member the ball valves are lowered and the suction effectis transmitted to the blocks and thereby to the blanks which areconveyed therewith.

The elastic bands 16 are held around the wheels 28, 29 by stretchingarms 30.

The apparatus described so far serves for translational travel of theblanks. The rotation of the blanks is effected as follows:

As seen in FIGS. 5 and 7, the shaft 17 of the rotatable member 14terminates at its lower end in a lever arm 31 having at its outer end aroller 32.

As shown in FIG. 7 two bars 33 and 34 are positioned along the path ofthe blocks 13 to contact rollers 32. In effect bars 33, 34 are linearcams, of which cam 33 contacts roller 32 to produce a quarter turn ofthe shaft 17 in one direction while the opposite cam 34 is effective toreturn the shaft 17 to its initial position.

Although the rotation will normally be a quarter of a turn, the cams canbe replaced to produce half a turn. By removing the cams or placing thearms 31 in a position where the cams do not contact the rollers, it isalso possible to displace the blanks without rotation.

Returning to FIG. 5, it has been noted that the blocks 13, slide on twosimilar members 20, 20', each provided with ball valves 22, 22, althoughonly one row of balls 22 was operated by the bar 24.

It is contemplated that alternate blocks 13 will operate alternate valvemembers 22 and 22. Thus by selectively subjecting the chambers 21, 21 tovacuum every member 8 may be subjected to suction or every other membermay be subject to suction. This allows adaptation of the device tovarious size blanks.

FIG. 8 shows very diagrammatically the overall conveyor mechanism, asmounted in a folding machine. Therein there are again shown the wheels28, 29 and the chains 27 causing the conveying members 8 (not shown) topass under the plate 10.

The partly folded blanks advance from left to right in FIG. 8 and passfirstly between accelerating rolls 35 which space the blanks from eachother to enable their subsequent rotation. The speed of the blanks atthe exit of rolls 35 will be for instance 1.2 times the normal conveyingspeed of the machine. The chains 27 are likewise displaced at thatincreased speed as are upper and lower conveying belts 36, 37 whichreceive the blanks after rotation and remove them for delivery to chain38. This chain is provided with stops 39 which engage the blanks anddeliver the same in correct position for subsequent folding by furtherfolding members of the folding machine. The conveyor mechanism as shownin FIG. 8 is positioned between zones A and B in FIG. 1 to effectrotation of the blanks.

Numerous modifications and variations of the invention will now becomeapparent to those skilled in the art without departing from the scopeand spirit of the invention if defined in the attached claims.

What is claimed is:

1. A conveying mechanism for folded blanks, said mechanism comprising aconveying member including a support member which is displaceable alonga path which is at least in part linear, and a rotatable member mountedin said support member and adapted for receiving a folded blank and forundergoing translational and rotational movement while supporting thefolded blank, and rotatable member having a flat outer surface forreceiving the blank, said outer surface having openings therein, meansfor establishing suction in said openings on selected portions of thepath of travel of the conveying member to maintain the folded blankagainst the outer surface of the rotatable member and a guiding memberlocated adjacent the conveying member and having a surface extendingparallel to and adjacent the outer surface of the rotatable member forengaging the folded blank and maintaining the folded condition thereofwhile the blank undergoes movement with the rotatable member.

2. A conveying mechanism as claimed in claim 1 wherein said supportmember has an outer surface which is coplanar with the outer surface ofthe rotatable member to define a flat outer surface for the conveyingmember.

3. A conveying mechanism as claimed in claim 1 comprising cam meansdisposed along the path of the support member for rotating the rotatablemember within the support member as the latter undergoes displacement.

4. A conveying mechanism as claimed in claim 1 comprising at least onerail supporting the support member for displacement along its path oftravel, said rail having a vacuum chamber and valve means for saidchamber, said means for establishing suction in said openings comprisingmeans on said support member for opening said valve means andestablishing communication between the vacuum chamber and said openingsin the rotatable member during the selected portions of travel of thesupport member along its path.

5. A conveying mechanism as claimed in claim 4 wherein said valve meanscomprises a plurality of successive valve members in said rail, springmeans urging each of the valve members to closed position, said meansfor opening said valve means comprising a bar on said support memberwhich opens successive valve members during displacement of the supportmember.

6. A conveying mechanism as claimed in claim 4 comprising meansconnecting a plurality of successive conveying members to form anendless chain.

7. A conveying mechanism as claimed in claim 6 comprising a second railsupporting the support members of the conveying members, the means onthe support members for opening said valve means being arranged so thatalternate conveying members are in communication with the vacuumchambers of opposite rails.

8. A conveying mechanism as claimed in claim 1 comprising elastic bandsconnecting a plurality of conveying members in succession, and guidemembers spaced apart to permit passage therebetween of the conveyingmembers and elastic bands, and guide members having outer surfaces whichare coplanar with the outer surfaces of the rotatable members.

9. A conveying mechanism as claimed in claim 1 wherein said guidingmember is constituted of transparent material.

10. A conveying mechanism as claimed in claim 1 comprising meansconnecting a plurality of successive conveying members together to forman endless chain, means for driving said chain along a path in which atleast one portion of the length of the chain is linear, said guidingmember being located adjacent the linear portion of said chain, meansfor feeding folded blanks between the guiding member and the linearportion of the chain at one end thereof and means for receiving theblanks at the other end of the linear portion of the chain.

11. A conveying mechanism as claimed in claim 1 wherein said means forestablishing suction in said openings is constituted by a suctionpassage in said conveying member in communication with said openings,and means on said conveying member for providing selective communicationof said suction passage with a suction source during travel of theconveying member.

References Cited UNITED STATES PATENTS 1,096,075 5/1914 Traver 19833 X2,618,207 11/1952 Hery et al. 198-33 X 2,812,079 l1/1957 Carnine et al.198180 X 3,189,158 5/1965 Locas 198-33 3,294,216 12/1966 Girardi 198-33X ANDRES H. NIELSEN, Primary Examiner.

' EVON c. BLUNK, Examiner.

R. I. HICKEY, Assistant Examiner.

